As for the graphics I can't say it superb, but with theme, they come along nicely I guess. The Golden Grail acts as a wild, so as any, will substitute all the other symbols on the reels, but not the scatter which is the Grail Maiden logo. Now about the free spins feature, if three Grail Maiden scatter logos appear anywhere on the reels the free spins feature will be activated giving you 5 free spins, the other bonus round is the Grail Bonus feature.
The Grail Bonus feature has 2 ways of activating it, to get 1 Maiden on the reel 1 and 1 Knight on the fifth reel, same counts or the bonus will be triggered if the Knight appears on the first reel and the Maiden on the first reel, but also it need at least one Grail on the second third or fourth reel, so then the bonus feature will be triggered.
As om the free spins, same number of free spins will be won in the bonus round feature. The good thing or what I like about the free spins feature,while getting at least 2 Grail on those 3 reels, they are stacked and will cover the entire reel and will stay like that till you finish your last free spin, so winnings from this round can be really big one.
The last time I played Grail Maiden slot was today in one of the WGS casinos, which was offered as a free tournament, so I was doing just great, triggered the bonus rounds few times, managed to pop up till 2nd place, but after I raised the bet to 25$ and lost it very fast, well better luck next time I guess. So I do recommend this game because I had decent wins from it and think it's worth of trying, good luck!